import React, {Component} from 'react';
import './index.css';

class OxGame extends Component {
    render() {
        return (
            <Game/>
        );
    }
}
function Square(props) {
    return (
        <button
            className="square"
            onClick={() => props.onClick()}
        >
            {props.value}
        </button>
    );
}

class Board extends React.Component {

    renderSquare(i) {
        return (
            //Square标签的属性会变成Square类的props的属性
            <Square
                value={this.props.squares[i]}
                onClick={() => this.props.onClick(i)}
            />
        );
    }

    render() {
        return (
            <div>
                <div className="board-row">
                    {this.renderSquare(0)}{this.renderSquare(1)}{this.renderSquare(2)}
                </div>
                <div className="board-row">
                    {this.renderSquare(3)}{this.renderSquare(4)}{this.renderSquare(5)}
                </div>
                <div className="board-row">
                    {this.renderSquare(6)}{this.renderSquare(7)}{this.renderSquare(8)}
                </div>
            </div>
        );
    }
}

class Game extends React.Component {
    constructor(props) {
        super(props);
        this.state = {
            history: [{
                squares: Array(9).fill(null),
            }],
            xIsNext: true,
        }
    }

    handleClick(i) {
        let history = this.state.history;
        const squares = history[history.length - 1].squares.slice();
        //squares[i] 可以防止重复点击
        if (calculateWinner(squares) || squares[i]) {
            return;
        }
        squares[i] = this.state.xIsNext ? 'X' : 'O';
        history.push({squares: squares});
        this.setState({
            history: history,
            xIsNext: !this.state.xIsNext,
        });
    }

    jumpTo(move) {
        const history = this.state.history.slice(0, move + 1);
        this.setState({
            history: history,
            xIsNext: move % 2 === 0,
        });
    }

    render() {
        const history = this.state.history;
        const current = history[history.length - 1];
        const winner = calculateWinner(current.squares);

        const moves = history.map((step, move) => {
            const desc = move ? 'Go to move #' + move : 'Go to game start';
            return (
                <li key={move}>
                    <button onClick={() => this.jumpTo(move)}>{desc}</button>
                </li>
            )
        })

        let status;
        if (winner) {
            status = "Winner: " + winner;
        } else {
            status = "Next player: " + (this.state.xIsNext ? 'X' : 'O');
        }
        return (
            <div className="game">
                <div className="game-board">
                    <Board squares={current.squares} onClick={(i) => this.handleClick(i)}/>
                </div>
                <div className="game-info">
                    <div>{status}</div>
                    <ol>{moves}</ol>
                </div>
            </div>
        );
    }
}
function calculateWinner(squares) {
    const lines = [
        [0, 1, 2],
        [3, 4, 5],
        [6, 7, 8],
        [0, 3, 6],
        [1, 4, 7],
        [2, 5, 8],
        [0, 4, 8],
        [2, 4, 6],
    ];
    for (let i = 0; i < lines.length; i++) {
        const [a, b, c] = lines[i];
        if (squares[a] && squares[a] === squares[b] && squares[a] === squares[c]) {
            return squares[a];
        }
    }
    return null;
}
export default OxGame;